I don´t really know to where the "Koblenz-Collection" has moved to...
There are some museums in Germany where you can see old tanks..
But the best of all ist the "Panzermuseum Munster". This is also "official supported" and you can see there a lot of tanks.. including Panther, Jagdpanther, Königstiger etc....
The following link of the museum is unfortunately in german.. But i think you will come clear with it
Stadt Munster - Home